Bituminous or other pitch concrete pavement.



UNITED STATES Patented Maren 21, 1905.

PATENT OFFICE.

BITUMINOUS OR OTHER PITCH CONCRETE PAVEMENT.

SPECIFICATION forming part of Letters Patent No. 785,396, dated March 21, 1905.

Application filed July 22, 1904. Serial No. 217,708.

To (0M whom it may concern..-

Be it known that I, JOSEPH HAY AMIEs, a citizen of the United States, residing at 3107 Columbia avenue, Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Bituminous or other Pitch Concrete Pavements, &c., of which the following is a specification.

My improvement relates to bituminous and other pitch pavements, roofing, flooring,posts, steps, ties, conduits, artificial lumber, and like utilities.

It consists in the novel manner in which water, mineral or fibrous materials, quicklime, sulfur, and bituminous and other pitch elements are combined and applied without the arbitrary employment of artificial heat to produce desirable results in procuring'compositions for said pavements, &e.

Referring particularly to pavements, by the usual practice of manufacturing the same the pitch and mineral matters are necessarily heated to such an extent as to greatly injure them. The heat demanded by said practice cannot be procured without machinery nor can the elements be combined by hand. This necessitates the investment of large capital and stationary or portable plants.

By my method machinery is non-essential and the mixing of the elements can be rapidly and conveniently done by unskilled handlabor.

In a days work of laying one thousand square yards of pavement by the usual method one hundred cubic yards of mineral matters must be heated to 480 Fahrenheit and ten tons of pitch to 340 Fahrenheit. This necessity constitutes a very large part of the expense and inconvenience of the usual way of laying said pavements and makes the investment of large capital and the employment of costly machinery and skilled labor peremptory. By my method these necessities are obviated.

The many advantages and conveniences of my method, as well as the great increase in the quantity of the work, will become evident when I disclose my process, which I now proceed to do.

I select mineral matters free from dust and dirt. They must be duly proportioned as to sizes to secure the greatest possible inherent stability of the mass. The said mineral matters when hand-labor is employed are put in the most convenient position, usually upon a mixing-board. They are then dampened with a due quantity of water and stirred until the surfaces of the mineral matters are coated therewith. I have previously reduced my quicklime and hard asphalt and sulfur to a pulverized condition. These three elements are carefully mixed in a dry state and in due quantities. By this procedure these elements become thoroughly separated and divided. I now sieve or thinly sprinkle this combination over the already-dampened mineral matters and effectively stir and mix them together. Very soon the quicklime, having absorbed the water, begins to slake. It reaches at the maximum of the slaking 300 Fahrenheit. The lime-coated mineral matters therefore present hot surfaces, and the heat produced by the slaking lime is sufiicient to melt the flour of sulfur and the dust of asphalt. I now sprinkle a due amount of flux, such as maltha or asphlate, oil or other suitable oil in a cold state over the mass, the stirring and mixing continuing.

When the flux comes into contact with the hot mass, the heated vapors arising therefrom cause it to violently foment, during which the movements of the flux are free and easy and are 'not unlike those of oil on a damp heated surface. This enables rapid and competent handmixing. The melted pulverized asphalt and sulfur readily combine with the flux, for which they have aifinity and which is eiIectively enforced by their resistance to the said hot vapors. I may now give the composition to the rakers close at hand, who rake it to a face prepared for desired compression by tam ping and rolling. This work is facilitated by the use of special heated tools. Very heavy heated rollers or tamper-s, or both combined, should preferably be used. If, however, the com-position is not to be immediately laid in the street, but is to be accumulated to be used at a deferred time, I then more freely dampen the mineral matters and do not use the full portion of lime with the sulfur and dust of asphalt. The composition in this case will remain soft and pliable as long as required, provided the evaporation of the water is prevented. When I come in this case to offer the composition to the rakers, I add and stir in the withheld portion of the'quicklime, which unites with the retained moisture, which it assumes and eliminates by slaking, and thereby producing heat enough to permit of perfect raking and facing. The composition is sufficiently heated by the added slaking lime and is in a perfect condition for condensation by tam ping and rolling after being placed upon a suitable street or road bed. The added lime dries the mass and causes it to.harden and toughen. I usually sweep over the surface sufficient Portland cement to secure uniform color and fill the face voids.

I have heretofore described the making of a composition for bituminous macadam roads. Should I make sheet-asphalt pavements, I proceed as above, excepting that I place upon the pavement described a greater thickness of sharp sand or grit composition, made as before explained.

In making the composition for flooring, roofing, &c., where weight is a consideration, I substitute fibers such as comminuted paper or paper-pulp, sawdust, peat, cut hay, and the like-for the mineral matters. In making steps, conduits, posts, ties, &c., where weight is not of so much consequence, I may mingle fibers and mineral matters together and place these, when desirable, in shaping-molds designed for the purpose and then subjecting them to desired compression.

I will now explain the reasons for my process.

In having clean mineral matters free from dust and dirt I am enabled to use a needed quantity of lime. Otherwise the lime would unite with the dust and dirt and form an uncontrollable paste, preventing it from coating the surfaces of the larger materials. The same is true of the fiuxing element. The lime used is sufiicient alone to form a paste to fill all the fine voids in the mass. The dampening of the surfaces of the mineral matters is unique and essential. The fine dust elements are held to the surfaces of the clean damp materials when they come in contact therewith and do not move about and reassemble, but effectively coat all the surfaces of the mineral or fibrous materials. If dry materials were used, this would not be the case; but the finelypulverized elements would riddle through and assemble and when the water was added form a paste that could not be easily separated, and therefore it would become impossible to secure a desirable mixture and the heat of the slaking lime would not be distributed and become nearly as effective in giving hot surfaces to the said materials, nor would it as ef- 5 fectively melt the sulfur and the dust of asphalt. In reducing the sulfur and asphalt to a pulverized condition and mixing them with the dry fine quicklime they become exposed to the most intense heat of the slaking lime. The temperature thus secured is very great, because in slaking the lime it expands to three and one-half volumes, thus providing all the heat I require; but this fact grows out of the way in which I apply my elements. The sulfur is used to increase the hardening of the asphaltic cement, and when found to be superfluous it can be omitted. In adding the flux at a desired time I am enabled to employ the violent fomentation described in securing perfect mixing with easy and rapid hand labor. It is evident, however, if I lind it desirable I may unite my hard asphalt and my fluxing elements by the application of artificial heat and while hot add them to the sulfur and lime and other materials after the same have become heated by the slaking lime. I have found by careful practice, however, no advantage in this; but the inconvenience and nuisance of the heating-pots used to melt the said elements and the cost of the fuel comsumed make this way undesirable. When I follow the above course, I have a very thick liquid, very viscid and hard to handle, and the mixing becomes almost impossible for hand labor, and I have found by extended practice that it is impossible to mix hot pitch with slaking lime or slaking lime with hot pitch and then incorporate sufficient materials to make a desirable composition for pavings, &c., owing to the fact that the lime and pitch unite to make a very thick paste and will not coat adue amount of materials. This I know by costly experience. The most effective and economical and convenient method to make the desired composition is by the process herein described. Furthermore, I have found in the United States large amounts of natural liquid asphaltum suitably composed which I can solely and separately use in my work and which will be sufficiently toughened and hardened by the application of the lime as I use it.

One great benefitaccruingfrom my process is the very large amount of flux I am enabled to use, which in many cases is as high as eighty per cent. This is permitted by the employment of clean mineral matters, enabling me to use a needed amount of lime to effect the desired hardening and toughening of the pitch. Such a large amount of flux, especially if it consists of a fixed element like asphalt-oil, will practically eliminate the aging of the pavement. To effect this, it is known to the art, is what has been sought to secure perfection in bituminous pavements. Besides, the employment of such a large percentage of flux conduces to the ability of hand-labor to procure perfect mixing. In the usual way,

even when the mineral matters are heated to 4:80 Fahrenheit and the pitch to 340 Fahrenheit, owing to the small amount of flux that can be used the pitch is so stifi" and viscid that hand-labor cannot be employed in mixing the elements. The pavements laid in the usual way, while often too soft for summer use, are yet hard enough in winter to crack and break away and rapidly granulate, and owing to the small amount of flux used oxidation becomes complete in about three years, and thereafter the pavements as generally at present laid become unfit for extended use. By my method *and for reasons stated these difficulties are avoided.

Perhaps the most practical of the benefits accruing from my process is the extreme reduction in cost 1 effect in laying bituminous pavements. I am for this reason enabled to bring a perfect bituminous macadam pavement into triumphant displacement of the imperfect stone road. The common stone road costs from two hundred and fifty to three hundred and fifty dollars per mile per year for maintenance, whereas in my case little or no cost will occur for maintenance for the first ten years and but a small com parativeamount for the second ten years. The faults of the ordinary macadam road, which are many, will not occur when my process is employed.

It has been shown in other uses of slaking lime in combination with pitch that it does harden and toughen the said pitch and practically eliminates the aging thereof, and it is herein disclosed how a process can be employed to utilize this fact in application tosecure compositions embracing the demands of practical road-making.

Having now full y disclosed my process, what I desire to secure by Letters Patent of the United States is 1. The herein-described process of procuring compositions for bituminous and other pitch pavements, &c., which consists in using clean, suitably-proportioned mineral matters, then sprinkling or pouring thereon a sufficient amount of water, then stirring them until the surfaces are dampened therewith, then siev-.

ing or throwing thereon finely granulated quicklime and the dust of hard asphalt and the flour of sulfur in due quantities, the said granulated quicklime and the dust of hard asphalt and the flour of sulfur having been previously incorporated together while in a dry state, then when the lime has begun to slake, sprinkling or pouring on the mass the due amount of unheated fluxing element, such as maltha or asphalt or other suitable oil, then mixing these all thoroughly together, then placing the same in a street or road bed or other desirable situation, then subjecting the whole to desired compression, substantially as specified.

2. The herein-described process of procuring compositions for bituminous or other pitch pavements, &c., which consists in dampening suitable elements with water to a desired extent, then adding therewith mixed granulated quicklime, dust of asphalt and Hour of sulfur,

in desired proportions, then pouring thereon a due amount of suitable fluxing material, and thoroughly mixing them together, then preserving the mass from exposure to the air toprevent evaporation of inherent moisture, for a deferred desirable time, then when needed for use, adding thereto and mixing therewith the withheld portion of granulated quicklime, for the purpose set forth and specified.

3. The herein-described process of procuring compositions for bituminous or other pitch pavements, &c., which consists in dampening suitable fibrous materials with water to a desired extent, then mixing therewith granulated quicklime, the dust of hard asphalt and the flour of sulfur, in due proportions, then sprinkling or pouring thereon a due amount of suitable fiuxing materials and thoroughly mix'ing them together, then forming this composition into the shapes desired in molds designed for the purposes, then subjecting it to tamping or pressure to secure desired density, for the purpose set forth and specified.

4. The herein-described process of procuring composition for bituminous pavements, &c., which consists in dampening suitable elements with water, then sieving or throwing thereon mingled granulated quicklime and the flour of sulfur, then sprinkling or pouring thereon hot asphaltic cement, then mixing them together, then subjecting the same to suitable compression under conditions set forth and specified.

In testimony whereof I affix my signature in I presence of two witnesses.

JOSEPH HAY AMIE S.

l/Vitnesses:

WALTER C. BLAKELY, MARY E. HAMER. 

